import java.util.ArrayList;

public class Test1 {
    public static ArrayList<Character> func(String str1, String str2){
        ArrayList<Character>arrayList=new ArrayList<>();
        for (int i = 0; i < str1.length(); i++) {
            char ch=str1.charAt(i);
            if(!str2.contains(ch+"")){
                arrayList.add(ch);
            }
        }
        return arrayList;
    }


    public static void main(String[] args) {
        ArrayList<Character>ret=func("welcome to bit","come");
        for (int i = 0; i < ret.size(); i++) {
            System.out.print(ret.get(i));
        }
    }
}
